Motor is running away!!

DannyB-67

New member
So I have a '67 mustang coupe with the inline 200 4 speed. I have recently changed the carburetor out from a single barrel auto lite to a two barrel Holley w/ manual choke. All new hoses (radiator, vacuum, fuel), new throttle cable, new battery, battery cables, starter solenoid, alternator, voltage regulator, constant voltage regulator, fuel pump, thermostat and housing. Rewired the front end. New headers and gasket. With all this being done, when I start the car it takes off and keeps going. I have no clue what it could be right now. I've gone through three gaskets for the adaptor for the two barrel thinking that was it, but it's not. I went to a 3/8 composite mounting gasket for the carb its self. Only thing I can think of now is to put a vacuum gauge to it and see what it's pulling. But I'm sure there is not a vacuum leak. I have the exhaust off right now so open headers could that be the issue? Could it have something to do with the choke bc I can pull the cable fine but have to get out of the car to release the cable so it may not be mounted right. I have put it into gear with my foot on the brake and no change. Just a little frustrating bc I put new wheels and tires on and haven't been able to drive it a foot. Any advice or tips would help I'm all ears and willing to try anything to get her on the road. Thanks!
 
DannyB-67":35znc0xs said:
So I have a '67 mustang coupe with the inline 200 4 speed. I have recently changed the carburetor out from a single barrel auto lite to a two barrel Holley w/ manual choke. All new hoses (radiator, vacuum, fuel), new throttle cable, new battery, battery cables, starter solenoid, alternator, voltage regulator, constant voltage regulator, fuel pump, thermostat and housing. Rewired the front end. New headers and gasket. With all this being done, when I start the car it takes off and keeps going. I have no clue what it could be right now. I've gone through three gaskets for the adaptor for the two barrel thinking that was it, but it's not. I went to a 3/8 composite mounting gasket for the carb its self. Only thing I can think of now is to put a vacuum gauge to it and see what it's pulling. But I'm sure there is not a vacuum leak. I have the exhaust off right now so open headers could that be the issue? Could it have something to do with the choke bc I can pull the cable fine but have to get out of the car to release the cable so it may not be mounted right. I have put it into gear with my foot on the brake and no change. Just a little frustrating bc I put new wheels and tires on and haven't been able to drive it a foot. Any advice or tips would help I'm all ears and willing to try anything to get her on the road. Thanks!

Not having the exhaust hooked up can cause some small differences in tuning, though it won't keep you for getting it running good. For the optimal in your tune though it will require you that retune once exhaust is hooked up again for street use as well as having an air cleaner installed just as the car will be operated. More importantly though it makes it harder to hear other problems you might have. Yes a vacuum gauge will be helpful in your tuning and diagnosing of your engine.

Now Have you checked your wet fuel float level setting yet on your Holley? Yes you also need too go over that choke linkage carefully to find out what's wrong or you can just set it to full open for now and also make sure that the fast idle cam is compleatly disengaged so it isn't holding the throdle linkage open more then the curb idle setting. IE it's fast idle adjustment screw is off the index Mark so it isn't holding the throdle linkage open. Good luck
 
ditto bubba's 2nd paragraph (from how U explain it).
Could B in the throt. cable,
choke
the linkage on the carb (there's 'fingers' & 'steps' there)
even a wrinkle in the carpet in the cab that holds down the gas peddle
a/c housing presses on the carb linkage…
I'm thinkin those sorts of things rather than vacuum, tune up, etc
 
Hi x2 bubba. Sounds like you are stuck on high idle. I'm not sure if the choke will open with the cable unless you push the gas pedal open a little. My hunch is that the fast idle cam is holding the choke cable in place so you can't push it in. With the car off, press the gas pedal down and see if the choke cable operates the choke. Also figure out how to lower that high idle. There is a lot to learn about the Holley 2 barrel, including cold adjustments, warm adjustments, ported vacuum etc. Not to mention a throttle return spring. Good luck
 
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